Cream separator drive



Aug. 31, 1948. P. B. SHEE 2,4485196 CREAM SEPARATOR DRIVE Filed April 15, 1944 Patented Aug. 31, 1948 CREAM SEPARA' IOR DRIVE Parke B. Shee, Oak Park, IlL, assignor to Sears, Roebuck and 00., Chicago, 111., a corporation of New York Application April 13, 1944, Serial No. 530,916

1 Claim. 1

This invention relates to centrifugal cream separators, and it is particularly concern-ed with the drive connection between a motor and the centrifugal bowl or separating element of the machine. One object of the invention is to provide a new and improved drive connection for a separator of this type.

Another object of the invention is to provide a motor having a hollow shaft in combination with the rotary element of the cream separator and a spindle therefor extending into the hollow shaft of the motor with clearance and with yieldable bearing means for the spindle permitting the rotor to seek its own axis of rotation which may not exactly coincide with that of the motor shaft. It is also an object of the invention to provide a drive coupling between the motor and the rotor of a centrifugal separator which will automatically release the rotor when the motor speed drops below that of said rotor or when the motor is stopped so that the rotor may contlnue spinning under its own momentum.

I Other objects and advantages of the invention will appear from the following description taken in connection with the drawings in which:

Fig. 1 is a side elevation of a cream separator embodying this invention with certain parts broken away or omitted to somewhat condense the view.

Fig. 2 is an enlarged partial elevational view partly in section indicating the location of the bowl or rotor of the separating mechanism and the relation thereto 01 an electric driving motor together with drive connections between said parts.

Fig. 3 is a transverse detail section taken as indicated at line 33 on Fig. 2.

Fig. 4 is an axial detail section showing the spring drive connection substantially as in Fig. 2, but on a larger scale.

While there is shown and described herein certain specific structure embodying the invention, it will be manifest to those skilled in the art that various modifications and re-arrangements of the parts may be made without departing irom the spirit and scope of the invention, and that the same is not limited to the particular form herein disclosed, except in so tar as indicated by the appended claim.

The cream separator shown in Fig, 1 i supported upon a pedestal comprising a base portion I and a hollow column 2 surmounted by a casing 3 having a. dome-shaped top- 4 within which there is located the feed cup indicated in dotted outline at 5 and the bowl or rotor 6 of the centrifugal separating mechanism. A bracket arm 1 extending from the casing 3 supports a vessel or tank 8 into which the milk is pour-ed and from which it is released by a control valve 9 to the iced cup 5 of the separator. A discharge spout for the separated cream is shown at .l l and It may be understood that in a, machine of [this type the bowl or rotor 6 revolves at a suitable separating speed so that unless its center of gravity coincides quite accurately with its axis of revolution, a violent vibration will be set up which may. seriously injure the machine or whichwill at least cause rapid wear of the hearings and reduction in the efliciency. The present inven-- tion thereforeprovides a construction which permits the bowl 6, to seek its own axis of revolution without strain or injury to the drive connections. The driving motor l6, instead of having the usual solid shaft, is provided with a hollow shaft I'I suitably journaled for rotation in any preferred manner and the motor 46 is disposed within the hollow-column 2 of the pedestal with the axis of its shaft extending vertically therein and in substantial alinement with the axis of the bowl 6.

Within the hollow shaft ll of the motor 16 there extends a spindle I8 having an external diameter which is somewhat less than the internal diameter of the shaft i! so as to provide some clearance if the spindle 18 should be slightly misalined with the shaft l'l. At its upper end said spindle is atormed with a transverse slot l9 and the bowl 6 includes a key element 20 which interenga'gcs with the slot I! to provide a driving connection between the spindle and bowl. This upper slotted end of the spindle fits into the bore of the central hub 2| of the bowl 6, said bore fitting snugly over the upper end portion of the spindle l8 to position the bowl firmly thereon. Alt the lower end of the hollow motor shaft ll there is inserted a plug 22 having a reduced upstanding terminal 23 which extends adjacent the reduced lower end 24 of the spindle l8 as best seen in Fig. 4. A hardened steel ball 25 is interposed between the part 23 and the portion 24 and a coil spring 26 yielding-1y embraces said reduced portion 23 of the plug and the reduced portion 24 of the spindle, these parts being preferably of the same diameter. The normal internal diameter of the coil spring 26 is slightly A lug l3 sup-.

the coil spring 26":andnthe parts23 and 24 causes the coil to be tigh tened around said parts so as to serve as an eifective drive connection between, But when the separator bowl 6 has attained its desi rerlirortwthe motor and the spindle l8.

ti-on-al velocity, a slackening of the motor speed will produce a reversal of theparf, 2 3 wi-thre spect to the part 24 as the howl continues to spin under its momentum, and this relative reverse rotation will release thefrietional' torque.

upon the driving spring 26, allowing the spindle I 18 to overrun the motor shaft and to continue spinning quite freely even after the motor l6 has stopped; This is a safety factor allowing the bowl to spin if the motor has Stopped for any reason.

already noted, the separator bowl 6 and its spindle i=8 rotating at a high'speed will have a strong tendency to seek their'own axis of rotation, depending upon the exact location of the center of gravity of the parts. To permit this, a yielding bearing is-prov-id'ed for theupper end ofthe spind l'e 1:8 adjacent its connection with the bowl 6. This bearing is shown in Fig. 2 as comprising an inner ball race 30 fixed to the-spindle I8; an outer ball race 31 and a seriesof' bearing balls 32 interposed between the raceways. bearing restson a flange 33 projecting inward.

from a collar 34' formed on the casing 3 and ispositioned radially by springs 35 supported in sockets'36 inthe collar, with threadedplugs 31 backing up said springs-and adjustable for tensioni-ngthem. The internal wall of the collar 34 above the flange 33 is of such a diameter as to provide clearance around the outer ball race 3| so-that-if the spindle tends to assume al positionzi'n: which it is not strictly coaxial with the hollow-shaftl 'l the springs 36 may yield and. the

spindle: F8 may shift while thebowl 6 is revolv ing so as to allow the bowl and spindle to assume their naturali position ofrotation in a; condition:

or running balance It this results in a slight misalinement of! the spindle t8 witlr respect" to The ball the axis of the hollow shaft l1 and the reduced terminal 23 the flexibility of the drive spring 26 will permit accommodation of the parts.

The construction shown permits of a relatively compact arrangement with the spindle I8 of suflicient length to accommodate its upper end to a self-centered position of the rotor 6 without producing undue obliquity of the spindle. As shown, the upper end of the casing of the motor [6 includes a cylindrical portion 38, which fits snugly into a recess 39 in the annular part 34 ofqtheoasin-g 3 and adjacent this portion 38 the motor casing may have lugs or ears 40 arranged to receive screws-41 which extend upwardly into tl'ie'transverselower Wall of the casing 3 for anchoring themotor in position.

' ,Iiaclaim-z,

In a centrifugal separator including a bowl, a

" spi'ndledepending from said bowl, a motor having ill) a hollow vertical shaft with a bearing of relatively: short-axial extent for the lower end of said spindle. said bearing permitting transaxial movem'ent of said spindle relative to said shaft, radiallyyieldable means associated with said spindle and remote from" the lower end of said spindle and tending to maintainsaid spindle coaxial with said shaft, said shaft having a coaxial projection, a thrust bearing between said projection and spindle and on which the bottom of said'spindle rests,

and'aclutch spring embracing and bridging said projection andspindle and operative to transmit a one-way drive from said shaft to said spindle while permitting said spindle to rotate about an axis other than the axis of said shaft. I

- 1 PARKE' B. SHEE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

